- and Electroproduction of Single Hadrons and Resonances

Production of single hadrons and resonances emerges as a promising field for the study of Quantum Chromodynamics at HERA. Four recent studies are presented here to illustrate the scope and reach of the technique: light mesons and resonances test the universality of hadroproduction, strange particles challenge the hadronisation models or directly probe the quark content of the proton sea while the first observation of K - K resonant states offers a glueball candidate.